Effect of challenging neck anatomy on mid-term migration rates in AneuRx endografts

"Redo" 2D-3D Fusion Technique during Endovascular Redo Aortic Repair

PURPOSE

The present study aims to describe a new 2D-3D fusion registration method in the case of endovascular redo aortic repair and compare the accuracy of the registration using the previously implanted devices vs. bones as landmarks.

MATERIALS AND METHODS

This single-center study prospectively analyzed all the patients that underwent elective endovascular re-interventions using the Redo Fusion technique between January 2016 and December 2021 at the Vascular Surgery Unit of the Fondazione Policlinico Universitario A. Gemelli (FPUG)-IRCCS in Rome, Italy. The fusion overlay was performed twice, first using bone landmarks (bone fusion) and the second using radiopaque markers of a previous endovascular device (redo fusion). The pre-operative 3D model was fused with live fluoroscopy to create a roadmap. Longitudinal distances between the inferior margin of the target vessel in live fluoroscopy and the inferior margin of the target vessel in bone fusion and redo fusion were measured.

RESULTS

This single-center study prospectively analyzed 20 patients. There were 15 men and five women, with a median age of 69.7 (IQR 42) years. The median distance between the inferior margin of the target vessel ostium in digital subtraction angiography and the inferior margin of the target vessel ostium in bone fusion and redo fusion was 5.35 mm and 1.35 mm, respectively (p ≤ 0.0001).

CONCLUSIONS

The redo fusion technique is accurate and allows the optimization of X-ray working views, supporting the endovascular navigation and vessel catheterization in case of endovascular redo aortic repair.

The intervention seasons of thoracic endovascular aortic repair impacted the outcomes for patients with type B aortic dissection

Purpose

The objective of this research was to investigate whether seasonal variations influence the outcomes of type B aortic dissection (TBAD) patients with thoracic endovascular aortic repair (TEVAR).

Patients and methods

From 2003 to 2020, a retrospective cohort study was performed, which included 1,123 TBAD patients who received TEVAR. Medical records were used to gather data on baseline characteristics. Outcomes including all-cause mortality and aortic-related adverse events (ARAEs) were tracked and analyzed.

Results

Of the 1,123 TBAD patients in this study, 308 received TEVAR in spring (27.4%), 240 cases in summer (21.4%), 260 cases in autumn (23.2%), and 315 cases in winter (28.0%). Patients in the autumn group had a significantly lower risk of 1-year mortality than those in the spring group (hazard ratio: 2.66, 95% confidence interval: 1.06-6.67, p = 0.037). Kaplan-Meier curves revealed that patients who underwent TEVAR in autumn had a lower risk of 30-day ARAEs (p = 0.049) and 1-year mortality (p = 0.03) than those in spring.

Conclusion

This study confirmed that TEVAR operated in autumn for TBAD was associated with a lower risk of 30-day ARAEs and 1-year mortality than in spring.

The Association between Device Instructions for Use Adherence and Outcomes after Elective Endovascular Aortic Abdominal Aneurysm Repair

OBJECTIVE

Aortic neck anatomy has a significant impact on the complexity of endovascular aortic aneurysm repair (EVAR), with concern that neck characteristics outside of instructions for use (IFU) may result in worse outcomes. Therefore, this study determined the impact of neck characteristics outside of IFU on perioperative and one-year outcomes and mid-term survival after EVAR.

METHODS

We identified all patients undergoing elective infrarenal EVAR from December 2014 to May 2020 in the Vascular Quality Initiative database. Neck characteristics outside of IFU were determined based the specific device IFU neck characteristics (Neck diameter, length, and angulation). Patients without one-year follow-up were excluded for the 1-year outcomes analyses (n=6,138 (40%)). We used multivariable adjusted logistic regression and Cox proportional hazard models to identify the independent associations between neck characteristics outside of IFU and our outcomes.

RESULTS

Of the 15,448 patients identified, 22.1% had neck characteristics outside of IFU, including 6.6% with a infrarenal angle, 6.8% with a neck length, 10.4% with a neck diameter, and 1.1% with a suprarenal angulation outside of IFU. Of these, 2.4% had more than one neck characteristic outside of IFU. Patients with neck characteristics outside of IFU were more often female (27.9% vs. 15.0%, P<.001) and were older (median age 75 vs. 73, P<.001). EVAR patients with neck characteristics outside of IFU had higher rates of type Ia endoleaks at completion (4.8% vs. 2.5%, P<.001), perioperative mortality (1.2% vs. 0.6%, P<.001), one-year sac expansion (7.1% vs. 5.3%, P=.017), and one-year reinterventions (4.4% vs. 3.2%, P=.03). In multivariable adjusted analyses, neck characteristics outside of IFU were independently associated with type Ia completion endoleaks (OR 1.6, [1.3-2.0], P<.001), perioperative mortality (OR 1.8; [1.2-2.7]; P=.005), one-year sac expansion (OR 1.4; [1.0-1.8]; P=.025) and one-year reinterventions (OR 1.4; [1.0-1.9]; P=.039). Unadjusted mid-term survival was lower for patients with neck characteristics outside of IFU than for patients without (5-year survival 84.0% vs. 86.7%, log-rank<.001). However, after adjustment, survival was similar for patients with neck characteristics outside of IFU to those within (HR: 1.1; [1.0-1.3]; P=.22).

CONCLUSION

Neck characteristics outside of IFU are independently associated with completion type Ia endoleaks, perioperative mortality, one-year sac expansion and one-year reinterventions among patients undergoing elective EVAR. These results indicate that continued effort is needed to improve the proximal seal in patients with neck characteristics outside of IFU undergoing EVAR. Also, in patients with severe hostile neck characteristics, alternative approaches such as open repair, use of a fenestrated or branched device, or endoanchors should be considered.

The Correlation Of Aortic Neck Length To Late Outcomes Following EVAR with the Ovation Stent Graft

BACKGROUND

Endovascular aneurysm repair (EVAR) performed outside manufacturers' instructions for use (IFU) due to short aortic neck for the treatment of abdominal aortic aneurysm (AAA) is associated with unfavorable outcomes. Newer endografts now have an indication for shorter neck aneurysms that previous endografts do not, but this cohort has yet to be evaluated individually. The aim of this study is to evaluate 5-year outcomes after EVAR in patients with short aortic necks (<10mm) using the Ovation stent graft.

METHODS

The study comprised 238 patients who underwent EVAR as part of the prospective international multicenter Ovation stent graft trials. The main inclusion criteria were AAA diameter ≥ 5cm, proximal parallel neck length ≥7mm, neck angulation ≤60° and bilateral iliac fixation length ≥10 mm. A clinical events committee adjudicated adverse events through 1 year, an independent imaging core laboratory analyzed imaging through 5 years and a data safety and monitoring board provided study oversight. Patients were divided into short neck (<10mm) and standard neck (≥10mm) groups. Endpoints included long-term survival, freedom from aneurysm-related mortality (ARM), freedom from type Ia Endoleak and freedom from reintervention.

RESULTS

Patients were predominantly male (81%) with a mean age of 73±8 years. Median follow-up time was 58 months (IQR 36-60). Out of 238 patients, 41 (17.2%) had a proximal neck length <10mm and would be considered outside the IFU with other stent grafts. Baseline characteristics were relatively similar between the two groups. The 5-year overall survival estimates were 77.8% for the standard neck group compared to 59.5% for the short neck group (P= .03) (Figure1). There were no differences in the 5-year freedom from ARM (99.2% vs. 100%, P= .7), freedom from type Ia Endoleak (96.3% vs. 96.3%, P= .8) and freedom from reintervention (77.9% vs. 79.7%, P= .7) between the standard and short neck groups, respectively. After adjusting for age and other potential confounders, short proximal neck was associated with a 2-fold increase in 5-year all-cause mortality [aHR(95%CI): 2(1.02-3.8), P= .04].

CONCLUSION

The Ovation endograft performed well in short AAA neck with no difference in 5-year type Ia Endoleak, reintervention and ARM rates. However, short proximal neck was independently associated with a two-fold increase in the risk of all-cause mortality at five years. These findings confirm the prior literature on the association of hostile neck anatomy with late mortality following EVAR.

Aortic endograft sizing and endoleak, reintervention, and mortality following endovascular aneurysm repair

OBJECTIVE

Endograft sizing for endovascular abdominal aortic aneurysm repair (EVAR) is not consistent despite published instructions for use (IFU). We sought to identify factors associated with over/undersizing, determine sex influence on sizing, and examine sizing effects on endoleak, reintervention, and mortality by analyzing data obtained from the W.L. Gore & Associates Global Registry for Endovascular Aortic Treatment (GREAT).

METHODS

All patients enrolled in GREAT undergoing EVAR were included for analysis. Proximal/distal aortic landing zones were compared with device implanted to assess sizing as related to IFU. χ²/Fisher exact tests were used to evaluate associations between IFU sizing and demographics. Logistic regression modeling was used to identify predictors of outside IFU sizing. Cox proportional hazards regression analyzed the relationship between sizing and endoleak, device-related reinterventions, and all-cause/aortic mortality.

RESULTS

There were 3607 EVAR subjects enrolled in GREAT as of March 2020. Of them, 1896 (53%) were within IFU for sizing, 791 (22%) were oversized, 540 (15%) were undersized, and 380 (10%) had both over- and undersized components. Factors predictive of use outside of IFU included female sex (P = .001), non-white race (P = .0003), decreased proximal neck length (P < .061), or larger iliac diameters (P < .0001). Women were more likely than men to have proximal neck undersizing and iliac limb oversizing, and men were more likely to have iliac limb undersizing. On multivariate analysis, undersizing of the proximal graft was associated with endoleak (hazard ratio [HR], 1.8) and aortic (HR, 60.5) and all-cause (HR, 18.0) mortality. Undersizing of iliac limbs was associated with endoleak (HR, 1.5) and device-related reintervention (HR, 1.4). Iliac limb outside IFU sizing was associated with aortic (HR, 2.6) and all-cause (HR, 1.3) mortality. Proximal and distal oversizing was not associated with adverse outcomes. Female sex was associated with mortality on univariate but not multivariate analysis.

CONCLUSIONS

Women undergoing EVAR with GORE EXCLUDER abdominal aortic aneurysm Endoprosthesis (W.L. Gore & Associates Inc, Flagstaff, Ariz) are more likely to have proximal stent-graft undersizing and iliac limb oversizing, whereas men are more likely to have undersized iliac limbs. Proximal aortic graft undersizing is associated with endoleak and all-cause/aortic mortality, whereas undersizing of iliac limbs is associated with endoleak and device-related reintervention. Oversizing was not associated with adverse outcomes.

Contemporary outcomes of endovascular abdominal aortic aneurysm repair in patients deemed unfit for open surgical repair

OBJECTIVE

Endovascular abdominal aortic aneurysm repair (EVAR) has been preferred to open surgical repair (OSR) for the treatment of abdominal aortic aneurysms (AAAs) in high-risk patients. We compared the perioperative and long-term outcomes of EVAR for patients designated as unfit for OSR using a large national dataset.

METHODS

The Vascular Quality Initiative database was queried for patients who had undergone elective EVAR for AAAs >5 cm from 2013 to 2019. The patients were stratified into two cohorts according to their suitability for OSR (fit vs unfit). The primary outcomes included perioperative (in-hospital) major adverse events, perioperative mortality, and mortality at 1 and 5 years. Patient demographics and postoperative outcomes were analyzed to identify the predictors of perioperative and long-term mortality.

RESULTS

Of 16,183 EVARs, 1782 patients had been deemed unfit for OSR. The unfit cohort was more likely to be older and female, with a greater proportion of hypertension, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, and larger aneurysm diameters. Postoperatively, the unfit cohort was more likely to have experienced cardiopulmonary complications (6.5% vs 3%; P < .001), with greater perioperative mortality (1.7% vs 0.6%; P < .001) and 1- and 5-year mortality (13% and 29% for the unfit vs 5% and 14% for the fit cohorts, respectively; P < .001). A subgroup analysis of the unfit cohort revealed that those deemed unfit because of a hostile abdomen had significantly lower 1- and 5-year mortality (6% and 20%, respectively) compared with those considered unfit because of cardiopulmonary compromise and frailty (14% and 30%, respectively; P = .451). Reintervention-free survival at 1 and 5 years was significantly greater in the fit cohort (93% and 82%, respectively) compared with that for the unfit cohort (85% and 68%, respectively; P < .001). The designation as unfit for OSR was an independent predictor of both perioperative (odds ratio, 1.59; 95% confidence interval [CI], 1.03-2.46; P = .038) and long-term mortality (hazard ratio [HR], 1.92; 95% CI, 1.69-2.17; P < .001). Advanced age (odds ratio, 2.91; 95% CI, 1.28-6.66; P = .011) was the strongest determinant of perioperative mortality, and end-stage renal disease (HR, 2.51; 95% CI, 1.78-3.55; P < .001) was the strongest predictor of long-term mortality. Statin use (HR, 0.77; 95% CI, 0.69-0.87; P < .001) and angiotensin-converting enzyme inhibitor use (HR, 0.83; 95% CI, 0.75-0.93; P < .001) were protective of long-term mortality.

CONCLUSIONS

Despite low perioperative mortality, the long-term mortality of those designated by operating surgeons as unfit for OSR was rather high for patients undergoing elective EVAR, likely owing to the competing risk of death from medical frailty. An unfit designation because of a hostile abdomen did not confer any additional risks after EVAR. Judicious estimation of the patient's life expectancy is essential when considering the treatment options for this subset of patients deemed unfit for OSR.

Endurant stent graft demonstrates promising outcomes in challenging abdominal aortic aneurysm anatomy

OBJECTIVE

We aimed to assess the 5-year safety and effectiveness outcomes of patients enrolled in the Endurant Stent Graft Natural Selection Global Post Market Registry (ENGAGE) who were treated outside the approved indications for use (IFU) of the Endurant stent graft.

METHODS

Our primary outcome measure was 12-month treatment success, defined as successful endograft delivery and deployment and the absence of type I or III endoleak, stent migration or limb occlusion, late conversion, and abdominal aortic aneurysm diameter increase or rupture. Secondary outcome measures included 30-day all-cause mortality, major adverse events, secondary procedures, technical observations, aneurysm-related mortality, and all-cause mortality within 12 months.

RESULTS

Demographic characteristics of ENGAGE patients treated outside (225 [17.8%]) and within (1038 [82.2%]) the IFUs were similar, except that female patients comprised a much higher percentage of the outside IFU group (19.1% vs 8.7%; P < .001). The outside IFU group presented with lower rates of coronary artery disease and cardiac revascularization and a greater number of symptomatic patients compared with the within IFU group (21.3% vs 15.0%; P = .020). Technical success was achieved in more than 99% of all patients. The outside and within IFU groups showed a comparable and low occurrence of uncorrected type I (0.9% vs 1.2%; P = 1.00) and type III endoleak (0.4% vs 0.3%; P = .54) immediately after device implantation. The 5-year freedom from type IA endoleaks was 89.4% vs 96.7% (P < .0001) for those patients outside and within the IFUs, respectively, although both groups had similar type III endoleaks through 5 years (P = .61). Stent graft limb occlusion estimated overall survival, and freedom from aneurysm-related mortality and endovascular interventions were comparable in both patient groups through the 5-year follow-up. The Kaplan-Meier estimates at 5 years showed a trend for low but increased need for type I or III endoleak correction procedures in the outside IFU group compared with the within IFU group (7.2% vs 5.2%; P = .099).

CONCLUSIONS

Differences were not observed in all-cause mortality, aneurysm-related mortality, and secondary procedures between within and outside IFU patients through a 5-year follow-up in the ENGAGE registry. Proximal necks with angulation or diameters outside the IFUs were the most common reasons for patients identified as being outside IFU, and the cohort had increased incidence of type IA endoleaks. Despite the challenges presented from the broad range of aortic and abdominal aortic aneurysm morphologies, the Endurant stent graft showed promising 5-year outcomes.

Fenestrated/Branched Endovascular Aortic Aneurysm Repair Using a Supraceliac Aortic Proximal Seal Zone Versus an Infraceliac Aortic Proximal Seal Zone

BACKGROUND

Fenestrated/branched endovascular aneurysm repair (F/B-EVAR) achieves more extensive proximal seal than conventional infrarenal devices, thereby increasing aneurysm exclusion durability. Optimal seal zone length remains undefined. We assessed relative risks and benefits of extending the proximal seal above the celiac artery.

METHODS

The prospective database of all complex endovascular aortic aneurysm repairs at a single institution (institutional review board-approved, physician-sponsored investigational device exemption trial, 10/2010-6/2017) was used to classify repairs according to the number of target visceral-renal arteries incorporated: 4-vessel versus <4-vessel. Comparisons of aneurysm characteristics, perioperative details, and postoperative complications were performed, stratified by repair type. One-year survival, target artery patency, freedom from type 1 or 3 endoleak, and freedom from reintervention were estimated with Kaplan-Meier analysis.

RESULTS

Among 175 F/B-EVARs, 38% (n = 67) were 4-vessel and 62% (n = 108) were <4-vessel. Intraoperatively, there was no difference in mean contrast use (76 mL vs. 74 mL, P = non significant [NS]) or dose area product (63,428 mGy cm² vs. 96,015 mGy cm²), but there was increased median procedure time (4.8 hr, interquartile range [IQR] = 4.1-5.8 versus 3.6 hr, IQR = 2.9-4.1, P < 0.0001) and mean operating room direct costs ($52,532, standard deviation [SD] = 18,640 versus $40,128, SD = 15,135, P < 0.0001) in 4-vessel repairs. There were no differences in mortality (1.9% vs. 4.5%), paraparesis (0% vs. 3.0%), or paralysis (0.9% vs. 0%), all P = NS. There were no differences in one-year survival, target artery patency, or freedom from reintervention. There was a lower 1-year freedom from type 1 or 3 endoleak with 4-vessel repairs (82% vs. 94%, log-rank P = 0.02), driven by an increased rate of type 3 endoleaks. Endoleak resolution after treatment was equivalent in both groups (4-vessel, 10 of 12, 83% resolved; <4-vessel, 7 of 7, 100% resolved, P = NS).

CONCLUSIONS

With F/B-EVAR, utilization of a supraceliac seal zone, compared with an infraceliac seal zone, is associated with statistical differences in operative characteristics/resource utilization, but with negligible clinical significance. Further innovation to eliminate type 3 endoleaks at fenestrations/branches remains an unmet need. To achieve adequate F/B-EVAR proximal seal zone length, one should have a low threshold to incorporate the celiac artery.

Midterm results of endovascular aneurysm sealing to treat abdominal aortic aneurysm

BACKGROUND

Endovascular aneurysm sealing (EVAS) represents a novel approach to the treatment of abdominal aortic aneurysms. It uses polymer technology to achieve an anatomic seal within the sac of the aneurysm. This cohort study reports the early clinical outcomes, technical refinements, and learning curve during the initial EVAS experience at a single institution.

METHODS

Results from 150 consecutive EVAS cases for intact, infrarenal abdominal aortic aneurysms are reported here. These cases were undertaken between March 2013 and July 2015. Preoperative, perioperative, and postoperative data were collected for each patient prospectively.

RESULTS

The median age of the cohort was 76.6 years (interquartile range, 70.2-80.9 years), and 87.3% were male. Median aneurysm diameter was 62.0 mm (IQR, 58.0-69.0 mm). Adverse neck morphology was seen in 69 (46.0%) patients, including aneurysm neck length <10 mm (17.3%), neck diameter >32 mm or <18 mm (8.7%), and neck angulation >60 degrees (15.3%). Median follow-up was 687 days (IQR, 463-897 days); 37 patients (24.7%) underwent reintervention. The rates of unresolved endoleak are 1.3% type IA, 0.7% type IB, and 2.7% type I. There were no type III endoleaks. There have been seven secondary ruptures in this cohort; all but one of these patients survived after reintervention. Only one rupture occurred in an aneurysm that had been treated within the manufacturer's instructions for use (IFU).

CONCLUSIONS

The rate of unresolved endoleaks is satisfactorily low. The incidence of secondary rupture is of concern; however, when the IFU are adhered to, the rate is very low. The results of this study suggest that working within the IFU yields better clinical results.

Could Preoperative Neck Anatomy Influence Follow-up of EVAR?

BACKGROUND

The aim of the study was to assess the clinical utility of strict CT scan surveillance after endovascular abdominal aneurysm repair (EVAR) and evaluate whether the anatomy of abdominal aortic aneurysm (AAA) neck (favorable/hostile) influences regular imaging control.

METHODS

A retrospective study of AAA patients who underwent EVAR with aortobi-iliac endoprostheses during 2006-2013 was conducted. Exclusion criteria included other types of devices. Variables analyzed were technical and clinical success, morbimortality, complications (such as endoleaks, sac enlargement), reinterventions, reintervention-free survival, and survival rate. Preoperative CT scans were performed and repeated at 1, 6 (in selective cases), 12, and 24 months postoperatively. Patients were divided into two groups according to preoperative anatomic characteristics: group I (favorable neck) and group II (hostile neck: angle > 60°, length < 15 mm, diameter > 28 mm, and calcification or circumference thrombus ≥50%).

RESULTS

A total of 127 patients with AAA (96.8% male) were included in the study. The mean age of the patients was 75.9 years (range: 51-90 years). The mean AAA diameter was 62.1 mm. Hostile neck was found in 52 patients (40.9%). The technical and clinical success rate was 100% and 30-day mortality was 0.8%. The reintervention-free survival rate was 97.6%, 96.1%, and 93.7% and the survival rate was 97.6%, 96.9%, and 91.3%, during follow-up at 6, 12, and 24 months, respectively. Accumulated complications in proximal sealing occurred in 0%, 0%, and 1.6% in group I and 1.9%, 6.1%, and 7.7% in group II at 1, 12, and 24 months, respectively. Type II endoleaks occurred in 24.3%, 14.3%, and 11.4% in group I and 9.8%, 6.3%, and 6.8% in group II at 1, 12, and 24 months, respectively. No increased diameter was detected at 6 and 12 months. No differences were observed in reinterventions and mortality rate depending on anatomy.

CONCLUSIONS

CT scans performed at 6 and 12 months postoperatively did not detect complications or need for reintervention in patients with favorable necks, even in the presence of endoleaks type II, and could therefore be omitted. Hostile necks may compromise proximal sealing and require regular imaging follow-ups.

Push-Up Technique and Anatomical Deployment With the Endurant Stent-Graft System for Severely Angulated Aneurysm Necks

PURPOSE

To describe a technique suitable for treating severely angulated (>75°) necks during endovascular aneurysm repair using the Endurant stent-graft.

TECHNIQUE

In the push-up technique, the suprarenal stent is released early to fix the proximal stent-graft in place so that each stent in the neck can be deployed individually without displacing the device upward. It is important to push the delivery system up after each stent deployment to allow the fabric between the stents to fold up circumferentially. By doing so, there is minimal upward force applied to the suprarenal stent. Because the stents expand along the angulated neck while catching blood flow, this anatomical deployment is feasible, with hardly any change to the proximal neck shape after stent-graft implantation.

CONCLUSION

The push-up technique and anatomical deployment with the Endurant stent-graft system are effective and safe methods for treating aneurysms with severely angulated necks.

Impact of the Repositionable C3 Excluder System on the Endovascular Treatment of Abdominal Aortic Aneurysms With Unfavorable Neck Anatomy

Purpose: To analyze the midterm clinical outcomes among patients with favorable and unfavorable neck morphology for endovascular aneurysm repair (EVAR), specifically the impact of the repositionable C3 Excluder stent-graft on type I endoleak in patients with unfavorable neck. Methods: A retrospective review was conducted of 249 patients (mean age 74.3 years; 241 men) who underwent successful EVAR from January 2000 to December 2014 using either the traditional Excluder (n=140) or the C3 repositionable system (n=109). Unfavorable proximal aortic neck anatomy was defined by length <15 mm, angulation >60°, >50% circumferential thrombus, or >50% neck calcification. By these criteria, unfavorable neck anatomy was present in 71 (28.5%) patients (41 traditional Excluder and 30 C3 Excluder). The main endpoint was the incidence of type Ia endoleak and the need for a proximal cuff according to the type of neck anatomy. Comparisons between groups are reported as the odds ratio (OR) and 95% confidence interval (CI). Results: A proximal extension cuff for type Ia endoleak was needed in 4 (2.2%) patients with favorable neck anatomy compared to 7 (9.9%) patients with unfavorable neck (OR 4.76, 95% CI 1.3 to 16.8, p=0.014). Among the patients with unfavorable neck, a proximal cuff was implanted in 6/41 (14.6%) traditional Excluder stent-grafts vs 1/30 (3.3%) in the C3 Excluder group (OR 4.39, 95% CI 0.55 to 34.58, p=0.23). Median follow-up was 30.5 and 38 months for favorable vs unfavorable neck groups, respectively (p=0.29). Only 1 case of type Ia endoleak was registered at 6.5 years’ follow-up (traditional Excluder), with no device migration. Conclusion: Both Excluder stent-grafts provide good midterm clinical outcomes after EVAR in patients with unfavorable neck anatomy. Investigation of a larger cohort will be needed to identify if the C3 Excluder device offers any improvement over the traditional Excluder in terms of freedom from endoleaks.

Current aortic endografts for the treatment of abdominal aortic aneurysms

Endovascular Aneurysm Repair is a widely adopted method of treatment for patients with abdominal aortic aneurysms. The minimally invasive approach offered with EVAR has become popular not only among physicians and patients, but in the medical device industry as well. Over the past 25 years the global market for aortic endografts has increased rapidly, resulting in a wide range of devices from various companies. Currently, there are seven endografts approved by the FDA for the treatment of abdominal aortic aneurysms. These devices offer a wide range of designs intended to increase inclusion criteria while decreasing technical complications such as endoleak and migration. Despite advances in device design, secondary interventions and follow-up requirements remain a significant issue. New devices are currently being studied in the U.S. and abroad and may significantly reduce complications and secondary interventions.

Anatomical Features and Early Outcomes of Endovascular Repair of Abdominal Aortic Aneurysm from a Korean Multicenter Registry

Purpose:

To introduce a nation-based endovascular aneurysm repair (EVAR) registry in South Korea and to analyze the anatomical features and early clinical outcomes of abdominal aortic aneurysms (AAA) in patients who underwent EVAR.

Materials and methods:

The Korean EVAR registry (KER) was a template-based online registry developed and established in 2009. The KER recruited 389 patients who underwent EVAR from 13 medical centers in South Korea from January 2010 to June 2010. We retrospectively reviewed the anatomic features and 30-day clinical outcomes.

Results:

Initial deployment without open conversion was achieved in all cases and procedure-related 30-day mortality rate was 1.9%. Anatomic features showed the following variables: proximal aortic neck angle 48.8±25.7° (mean±standard deviation), vertical neck length 35.0±17.2 mm, aneurysmal sac diameter 57.2±14.2 mm, common iliac artery (CIA) involvement in 218 (56.3%) patients, and median right CIA length 34.9 mm. Two hundred and nineteen (56.3%) patients showed neck calcification, 98 patients (25.2%) had neck thrombus, and the inferior mesenteric arteries of 91 patients (23.4%) were occluded.

Conclusion:

Anatomical features of AAA in patients from the KER were characterized as having angulated proximal neck, tortuous iliac artery, and a higher rate of CIA involvement. Long-term follow-up and ongoing studies are required.

Systematic review and meta-analysis of migration after endovascular abdominal aortic aneurysm repair

Aim

To identify patients who are under higher threat for migration because of an old generation stent graft application.

Methods

A systematic review and meta-analysis of the literature was undertaken to identify all studies which included older generation endografts and data reporting on graft migration after EVAR. Outcome data were pooled and combined, and were calculated using fixed or random effects models.

Results

From 2000 to 2014, 22 retrospective studies were identified reporting on stent- graft migration after EVAR (8.6%). From those patients, 39% received re-intervention with the mean time of identification ranging from 12 to 36 months. Six of these retrospective nonrandomized studies were eligible for meta-analysis. AAA diameter (AAA diameter: 0.719 mm; 95% confidence interval [CI]: 0.00065–1.4384 mm; p = 0.00497) and neck length (neck length: 4.36 mm; 95% CI: 1.3277–7.394; p = 0.0048) were the only significant factors associated with stent- graft migration. Neck diameter and neck angulation did not have any important influence on stent-graft migration.

Conclusions

Patients with large AAA and short necks who were treated with older generation stent grafts such as AneurX and Talent are in higher risk for endograft migration than others. Stent- graft migration consists of an insidious and underestimated threat.

Performance of the Endurant stent graft in challenging anatomy

OBJECTIVE

This study aimed to compare perioperative and postoperative outcomes after endovascular repair of abdominal aortic aneurysms (AAAs) in patients with various neck morphologic features.

METHODS

Data from the Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE) were used for the analyses. Patients were categorized into three different groups according to proximal aortic neck anatomy: regular (REG), intermediate (INT), and challenging (CHA). REG was defined as AAAs with a proximal neck ≥15 mm combined with a suprarenal angulation (α) ≤45 degrees and an infrarenal neck angulation (ß) ≤60 degrees. INT was defined as AAAs with a proximal neck of 10 to 15 mm combined with α ≤45 degrees and ß ≤60 degrees or with a proximal neck of >15 mm combined with α ≤60 degrees and ß = 60 to 75 degrees or α = 45 to 60 degrees and ß ≤75 degrees. CHA was defined as infrarenal necks that exceed at least one of the three defining factors.

RESULTS

Overall, 925 patients (75.9%) had REG anatomy, 189 patients (15.5%) had INT anatomy, and 104 patients (8.5%) had CHA anatomy. Patient demographics and risk factors were similar. There was a significant difference in AAA diameter between the REG and CHA groups (59.4 mm vs 65.2 mm; P < .001). Technical success was similar among groups (REG 99.1% vs INT 99.5% vs CHA 97.1%). There were no differences in mortality or the need for secondary procedures within 30 days or at 1 year. A significantly higher rate of type I endoleaks within 30 days was seen in CHA compared with REG (adjusted odds ratio, 0.15; 95% confidence interval, 0.05-0.46) and INT (adjusted odds ratio, 0.08; 95% confidence interval, 0.01-0.70), but there was no difference at 1-year follow-up.

CONCLUSIONS

This real-world, global experience shows promising results and indicates that endovascular AAA repair with the Endurant stent graft (Medtronic Vascular, Santa Rosa, Calif) is safe and effective in patients with challenging aortic neck anatomy. However, long-term follow-up of patients is required to confirm results.

Endovascular aneurysm sealing for infrarenal abdominal aortic aneurysms: 30-day outcomes of 105 patients in a single centre

OBJECTIVE

Endovascular aneurysm sealing (EVAS) has been proposed as a novel alternative to endovascular aneurysm repair (EVAR) in patients with infrarenal abdominal aortic aneurysms (AAA). The early clinical experience, technical refinements, and learning curve of EVAS in the treatment of AAA at a single institution are presented.

METHODS

One-hundred and five patients were treated with EVAS between March 2013 and November 2014. Prospective data were recorded on consecutive patients receiving EVAS. Data included demographics, preoperative aneurysm morphology, and 30-day outcomes, including rates of endoleak, limb occlusion, reintervention, and death. Postoperative imaging consisted of duplex ultrasound and computed tomographic angiography.

RESULTS

The mean age of the cohort was 76 ± 8 years and 12% were female. Adverse neck morphology was present in 72 (69%) patients, including aneurysm neck length <10 mm (20%), neck diameter >32 mm (18%), β-angulation >60° (21%), and conical aneurysm neck (51%). There was one death within 30 days. The incidence of Type 1 endoleak within 30 days was 4% (n = 4); all were treated successfully with transcatheter embolisation. All four proximal endoleaks were associated with technical issues that resulted in procedure refinement, and all were in patients with adverse proximal aortic necks. The persistent Type 1 endoleak rate at 30 days was 0% and there were no Type 2 or Type 3 endoleaks. Angioplasty and adjunctive stenting were performed for postoperative limb stenosis in three patients (3%).

CONCLUSIONS

EVAS appears to be associated with reasonable 30-day outcomes despite the necessity of procedural evolution in the early adoption of this technique. EVAS appears to be applicable to patients with challenging aortic morphology and endoleak rates should reduce with procedural experience. The utility of EVAS will be defined by the durability of the device in long-term follow-up, although the absence of Type 2 endoleaks is encouraging.

Adherence to endovascular aortic aneurysm repair device instructions for use guidelines has no impact on outcomes

OBJECTIVE

Prior reports have suggested unfavorable outcomes after endovascular aortic aneurysm repair (EVAR) performed outside of the recommended instructions for use (IFU) guidelines. We report our long-term EVAR experience in a large multicenter registry with regard to adherence to IFU guidelines.

METHODS

Between 2000 and 2010, 489 of 1736 patients who underwent EVAR had preoperative anatomic measurements obtained from the M2S, Inc, imaging database (West Lebanon, NH). We examined outcomes in these patients with regard to whether they had met the device-specific IFU criteria. Primary outcomes were all-cause mortality and aneurysm-related mortality. Secondary outcomes were endoleak status, adverse events, reintervention, and aneurysm sac size change.

RESULTS

The median follow-up for the 489 patients was 3.1 years (interquartile range, 1.6-5.0 years); 58.1% (n = 284) had EVAR performed within IFU guidelines (IFU-adherent group), and 41.9% (n = 205) had EVAR performed outside of IFU guidelines (IFU-nonadherent group). Preoperative anatomic data showed that 62.4% of the IFU-nonadherent group had short neck length, 10.2% had greater angulation than recommended, 7.3% did not meet neck diameter criteria, and 20% had multiple anatomic issues. A small portion (n = 49; 10%) of the 489 patients were lost to follow-up because of leaving membership enrollment (n = 28), moving outside the region (n = 10), or discontinuing image surveillance (n = 11). There was no significant difference in any of the primary or secondary outcomes between the IFU-adherent and IFU-nonadherent groups. Aneurysm sac size change at any time point during follow-up also did not differ significantly between the two groups. A Cox proportional hazard model showed that IFU nonadherence was not predictive of all-cause mortality (hazard ratio, 1.0; P = .91). Similarly, IFU nonadherence was not identified as a risk factor for aneurysm-related mortality or adverse events in stepwise Cox proportional hazards models.

CONCLUSIONS

In our cohort of EVAR patients with detailed preoperative anatomic information and long-term follow-up, overall mortality and aneurysm-related mortality were unaffected by IFU adherence. In addition, rates of endoleak and reintervention after initial EVAR were similar, suggesting that lack of IFU-based anatomic suitability was not a driver of outcomes.

Standard endovascular treatment of abdominal aortic aneurysms in patients with very short proximal necks using the Endurant stent graft

OBJECTIVE

This study evaluated and compared the midterm results of endovascular aortic aneurysm repair with the Endurant (Medtronic Inc, Santa Rosa, Calif) stent graft system in off-label use in patients with short (<10 mm) proximal aortic necks and in patients treated according to device-specific instructions for use.

METHODS

This was a case-control (2:1) single-center retrospective analysis of prospectively collected data performed between September 2008 and December 2012. Analysis identified 19 elective patients with short (<10 mm) proximal necks and mild angulations (≤45°) treated with the Endurant stent graft and 38 patients matched for age, sex, and aneurysm diameter with proximal aortic necks ≥10 mm in length who met the instructions for use. End points included technical and clinical success and freedom from any secondary intervention, any type of endoleak, and aneurysm-related death.

RESULTS

The short-neck group was a mean ± standard deviation age of 71.7 ± 8.9 years, 84% were men, and their mean infrarenal aortic neck length was 6.1 ± 1.2 mm. Mean suprarenal and infrarenal angles were 110° ± 10.4° and 170° ± 15.4°, respectively. Aortic neck diameters were similar between the groups (26.6 ± 3.8 vs 25.7 ± 3.7 mm; P = .36). Primary technical success was achieved in all cases. Off-label patients were more likely to require additional proximal cuff deployment to successfully obtain a seal (21% vs 3%; P = .04). The two patient groups were similar in rates of perioperative mortality, morbidity, and complications. Mean follow-up of 24 ± 12 months revealed no differences in clinical success, freedom from reintervention, and aneurysm-related death. No type I endoleaks were observed in either group during the follow-up period.

CONCLUSIONS

The Endurant stent graft system applied off-label in patients with very short aneurysm necks (<10 mm) with mild angulation showed acceptable treatment results. These midterm results might suggest its use in carefully selected patients with very short neck anatomy. Long-term data are needed to verify the observed durability of the Endurant stent graft.

A computational framework for investigating the positional stability of aortic endografts

Endovascular aneurysm repair (Greenhalgh in N Engl J Med 362(20):1863-1871, 2010) techniques have revolutionized the treatment of thoracic and abdominal aortic aneurysm disease, greatly reducing the perioperative mortality and morbidity associated with open surgical repair techniques. However, EVAR is not free of important complications such as late device migration, endoleak formation and fracture of device components that may result in adverse events such as aneurysm enlargement, need for long-term imaging surveillance and secondary interventions or even death. These complications result from the device inability to withstand the hemodynamics of blood flow and to keep its originally intended post-operative position over time. Understanding the in vivo biomechanical working environment experienced by endografts is a critical factor in improving their long-term performance. To date, no study has investigated the mechanics of contact between device and aorta in a three-dimensional setting. In this work, we developed a comprehensive Computational Solid Mechanics and Computational Fluid Dynamics framework to investigate the mechanics of endograft positional stability. The main building blocks of this framework are: (1) Three-dimensional non-planar aortic and stent-graft geometrical models, (2) Realistic multi-material constitutive laws for aorta, stent, and graft, (3) Physiological values for blood flow and pressure, and (4) Frictional model to describe the contact between the endograft and the aorta. We introduce a new metric for numerical quantification of the positional stability of the endograft. Lastly, in the results section, we test the framework by investigating the impact of several factors that are clinically known to affect endograft stability.

A systematic review of protocols for the three-dimensional morphologic assessment of abdominal aortic aneurysms using computed tomographic angiography

The morphology of infrarenal abdominal aortic aneurysms (AAAs) directly influences the perioperative outcome and long-term durability of endovascular aneurysm repair. A variety of methods have been proposed for the characterization of AAA morphology using reconstructed three-dimensional (3D) computed tomography (CT) images. At present, there is lack of consensus as to which of these methods is most applicable to clinical practice or research. The purpose of this review was to evaluate existing protocols that used 3D CT images in the assessment of various aspects of AAA morphology. An electronic search was performed, from January 1996 to the end of October 2010, using the Embase and Medline databases. The literature review conformed to PRISMA statement standards. The literature search identified 604 articles, of which 31 studies met inclusion criteria. Only 15 of 31 studies objectively assessed reproducibility. Existing published protocols were insufficient to define a single evidence-based methodology for preoperative assessment of AAA morphology. Further development and expert consensus are required to establish a standardized and validated protocol to determine precisely how morphology relates to outcomes after endovascular aneurysm repair.

A meta-analysis of outcomes of endovascular abdominal aortic aneurysm repair in patients with hostile and friendly neck anatomy

BACKGROUND

An increasing number of abdominal aortic aneurysms with unfavorable proximal neck anatomy are treated with standard endograft devices. Skepticism exists with regard to the safety and efficacy of this practice.

METHODS

A systematic review of the literature was undertaken to identify all studies comparing the outcomes of endovascular aneurysm repair (EVAR) in patients with hostile and friendly infrarenal neck anatomy. Hostile neck conditions were defined as conditions that were not consistent with the instructions for use of the endograft devices employed in the selected studies. Outcome data were pooled, and combined overall effect sizes were calculated using fixed or random effects models.

RESULTS

Seven observational studies reporting on 1559 patients (hostile anatomy group, 714 patients; friendly anatomy group, 845 patients) were included. Patients with hostile anatomy required an increased number of adjunctive procedures to achieve proximal seal compared with patients with friendly anatomy (odds ratio [OR], 3.050; 95% confidence interval [CI], 1.884-4.938). Although patients with unfavorable neck anatomy had an increased risk of developing 30-day morbidity (OR, 2.278; 95% CI, 1.025-5.063), no significant differences in the incidence of type I endoleak and reintervention rates within 30 days of treatment between the two groups were identified (OR, 2.467 and 1.082; 95% CI, 0.562-10.823 and 0.096-12.186). Patients with hostile anatomy had a fourfold increased risk of developing type I endoleak (OR, 4.563; 95% CI, 1.430-14.558) and a ninefold increased risk of aneurysm-related mortality within 1 year of treatment (OR, 9.378; 95% CI, 1.595-55.137).

CONCLUSIONS

Insufficient high-level evidence for or against performing standard EVAR in patients with hostile neck anatomy exists. Our analysis suggests EVAR should be cautiously used in patients with anatomic neck constraints.

Outcomes of endovascular aneurysm repair in patients with hostile neck anatomy

OBJECTIVES

This study aims to evaluate outcomes following EVAR in patients with hostile neck anatomy (HNA).

METHODS

Data prospectively collected from 552 elective EVARs were analysed retrospectively. Data regarding neck morphology was obtained from aneurysm stent plans produced prior to EVAR. HNA was defined as any of; neck diameter >28 mm, neck angulation >60°, neck length <15 mm, neck thrombus, or neck flare.

RESULTS

552 patients underwent EVAR. Mean age 73.9 years, mean follow-up 4.1 years. 199 patients had HNA, 353 had favourable neck anatomy (FNA). There was a significant increase in late type I endoleaks (FNA 4.5%, HNA 9.5%; P = 0.02) and total reinterventions (FNA 11.0%, HNA 22.8%; P < 0.01), and a significant decrease in late type II endoleaks in patients with HNA (FNA 16.7%, HNA 10.6%; P < 0.05). There was no significant difference in technical success (FNA 0.6%, HNA 2.0%; p = 0.12), 30-day re-intervention (FNA 2.8%, HNA 5.0%; P = 0.12), 30-day mortality (FNA 1.1%, HNA 0.5%; P = 0.45), 30-day type I endoleaks (FNA 0.8%, HNA 2.5%; P = 0.12), 5-year mortality (FNA 15.1%, HNA 14.6%; P = 0.86), aneurysm-related mortality (FNA 1.7% versus HNA 2.0%; P = 0.79), stent-graft migration (FNA 2.5%, HNA 3.0%; P = 0.75), sac expansion (FNA 13.0%, HNA 9.5%; P = 0.22), or graft rupture (FNA 1.1%, HNA 3.5%; P = 0.05). Binary logistic regression of individual features of HNA revealed secondary intervention (P = 0.009), technical failure (P = 0.02), and late type I endoleaks (P = 0.002), were significantly increased with increased neck diameter.

CONCLUSIONS

HNA AAAs can be successfully treated with EVAR. However, surveillance is necessary to detect and treat late type I endoleaks in HNA patients.

Clinical factors increasing radiation doses to patients undergoing long-lasting procedures: abdominal stent-graft implantation

Background

An important negative factor of EVAR is the radiation acquired during long-lasting procedures. The aim of the study was to document the radiation doses of EVAR and to discuss potential reasons for prolongation of radiological procedures.

Material/Methods

Dose-area product (DAP) (Gy cm²) and air kerma (AK) (Gy) obtained during EVAR from 92 patients were analyzed retrospectively in regards to body mass index (BMI), angulations of aneurysm neck, length of aneurysm neck and occurrence of tortuosity of iliac arteries.

Results

Total AK for fluoroscopy differed significantly between normal BMI (373 mGy) and BMI 25–29.9 (1125 mGy) or BMI >30 (1085 mGy). Iliac artery tortuosities >45° and short aneurysm necks caused higher doses of total AK (1097 mGy and 1228 mGy, respectively) than iliac artery tortuosities <45° and long aneurysm necks (605 mGy and 720 mGy, respectively).

Conclusions

The main factors contributing to a high radiation dose being acquired by patients during EVAR are: BMI >25, tortuosity of iliac arteries >45° and short aneurysm necks.

Patients' radiation doses during thoracic stent-graft implantation: the problem of long-lasting procedures

BACKGROUND

This article investigates patient radiation doses during implantation of thoracic stent-graft. Aortic stengraft implantation can be disturbed by many factors, which, in turn, lead to prolongation of the procedure time and, as a consequence, increase the radiation dose.

METHODS

Measurements of radiation length (fluoroscopy and exposure), air kerma (AK) in grays, and dose-area product in grays·square centimeters were conducted simultaneously in 100 patients. The patients were analyzed retrospectively, regarding their body mass index (BMI), type of aneurysms, number of stent-graft parts, angulation of aorta, and coverage of the left subclavian artery.

RESULTS

Mean total dose-area product value for this kind of treatment was 361 Gy·cm2. This was caused by the fact that total mean AK was high for the cohort analyzed and reached 797 mGy. For 23 patients total AK was between 1 and 2 Gy, and for 3 it exceeded 2 Gy. In the remaining group, the maximal radiation dose was very high and exceeded 3 Gy. The total AK of patients with BMI within the range of 25 to 29.9 kg/m2 and with BMI greater than 30 kg/m2 significantly increased in comparison with the group of patients with BMI between 18 and 24.9 kg/m2 (p=0.00005 and 0.000001, respectively). During the study, a good correlation between AK and fluoroscopy time (r=0.6) and for AK (or dose-area product) and exposure time (r=0.66 or 0.81, respectively) was observed.

CONCLUSIONS

The main factors contributing to a high radiation dose being acquired by patients during thoracic stent-graft were BMI greater than 25 kg/m2, number of parts of the stent-graft, and angulation of the neck of aneurysm exceeding 60 degrees.